Loader



March 5, 1957 P. J. OMAN 2,783,904

LOADER Filed Dec. 14, 1953 2 Sheets-Sheet l Phi/ip B/,im- 'Oman ATTORNEY March 5, 1957 P, J OMAN 2,783,904

LOADER Filed Dec. 14, 1953 2 Sheets-Sheet JNVENTOR. Phi/0' Jim OmanATTORNEY -United States Patent This invention relates to concrete slabhandling devices.

One object of the invention lies in the provision of a gripping devicehaving a transversely spaced pair of claws and a cooperating clawpivotally united for scissor movement relative to each other for veryeffectively grasping concrete slabs to be lifted and handled by thedevice.

Another object of the invention lies in the provision of a concrete slabhandling device having a gripping device secured on the free end of avertically tiltable arm and having a pair of transversely spaced clawsxed relative to the arm at an acute angle and a cooperating clawpivotally united for scissor movement relative to said fixed claws andmoveable when open to a position in axial alignment with said boomwhereby the tixed claws may be thrust into the earth and under the edgeof an article to be grasped thereby.

Another object of the invention lies in the provision of a concrete slabhandling device which is admirably adapted for grasping slabs ofconcrete such as sections of sidewalks and removing them from the groundand elevating them for loading into a truck bed.

These and other objects of the invention will become apparent during thecourse of the following description. The nature and advantages of thisinvention will appear more fully from the following description and theaccompanying drawings wherein a preferred form of the invention isshown. It should be understood however that the drawings and descriptionare illustrative only and are not intended to limit the inventionexcepting insofar as it is limited by the subsequent appended claims.

In the accompanying drawings, forming a part of this specification;

Figure l is a side elevation of a tractor vehicle having a verticallytiltable boom supporting the gripping device of this invention;

Figure 2 is a plan view of the mechanism shown in Figure 1;

Figure 3 is a perspective view of the grippingV device and thesupporting arm disassociated from the tractor;

Figure 4 is a fragmentary vertical cross section as at line 4 4 ofFigure 2; and

Figure 5 is a fragmentary longitudinal vertical cross section as at line5 5 of Figure 2.

Referring now more particularly to the drawings, the numeral 10designates generally a movable support or tractor vehicle, here shown asa wheeled tractor having rear driving wheels 11 and front steeringwheels 12. The rear wheels 11 are journaled at the ends of axlesenclosed in axle housings 13.

A boom support frame 14 is secured to the tractor 10 in any suitablemanner as on the front and rear axles 15 and 13. The boom or arm 16 isprovided with 'a pair of transversely spaced beams 18 journaled forvertical tilting movement at 17 on the tractor 10 and these arms areprovided with depending angular frame members 19 pivotally secured at 2)to the end of piston rod 21 associated with hydraulic servo-motors 22secured to the Vframe 14 or the 'axle housings 13. It will thus be seenthat the arm 16 may be vertically tilted by action ofV motors 22.

The beams 18 are suitably strengthened by means of l truss bars 23,onesecured above each beam.18 at the extreme ends thereof and extendingover spacing plates 24 welded intermediate the length of theirrespective beamV 18. The arm is suitably cross braced as at 25 toprovide:

a rigid verticallyltiltable arm or boom 16.

At the free end of the arm 16 a transversely extend-i ing rod 26 ispassed through horizontal apertures 27 formed in axial alignment throughthe beams 18 and the rod is of suiiicient length so that its endportions 26 are: disposed outwardly of the outside marginal edge of the:beams 18. Before drilling or otherwise forming the: apertures 27, thebeams 18 are provided with metallic' plugs 28 thus forming enlargedsurfaces for supporting; the rod 26.

Intermediate the spaced beams 18, I provide concentric.

with the ro'd 26 a thick walled sleeve 29 which has bearings 30 pressedinthe opposed ends. The bearings 30 are adapted to fit over the rod 26snuglyand yet permit removal of the rod 26 when desired. Outside of thebeams 18, the rod supports the upper ends of rigid claws 31' by passingthrough apertures 32 formed therein. diagonal bracing transverselybraces claws 31. A washer 33 and cotter key 50 are provided to completethe structure and locate the various elements in their relativepositions and yet permit removal of the rod 26 when desired.

The claws 31 extend downwardly from the beams 18 at an acute Iangle andare provided with flanges 3l' which are welded or otherwise-formed onthe rear edges of the bars 34 `are bifurcated and receive the anges 18where 'removable pinsV 37 are employed to releasably secure the bracebars 34 to the arm 18. Claws 31 are provided with forwardly extendingfingers 38 which are disposed at approximately from the longitudinaldimension of the claws 31 and are adapted to be hooked under the edge ofa concrete slab.

Secured midway the length of the sleeve 29 and extending radiallytherefrom, I provide a cooperating claw 39 having a downwardly orinwardly turned finger 40 also disposed at substantially 90 from thelongitudinal dimension of the claw 39. The finger 40 is ixed in opposedrelation to the lingers v38, thus forming a device for gripping when theclaw 39 is moved toward the claws 31. The claw 39 is welded or otherwisesecured to the sleeve 29 and suitable gussets 41 are employed tostrengthen the claw against transverse pressures.

At substantially right angles to the claw 39, the sleeve 29 is providedwith a lever 42 extending radially therefrom and welded or otherwisesecured thereto and is supported by means of gussets 43. Angle bracebars 44 are welded or otherwise secured along both sides of the lever 42at a point spaced from the sleeve 29 and extend forwardly to a pointadjacent to the hook end or linger 40 of the claw 39 forming a rigidunit of the claw 39 and lever 42 and brace bars 44. The brace bars 44extend rearwardly beyond the lever 42 and define a bifurcation intowhich the transverse sleeve 45 provi-ded on the end of piston rod 46 maybe inserted and removably secured by means of a removable pin 47. Apiston rod 46 extends outwardly of a double acting hydraulic ram 48movement of which will cause the claw 39 to pivot about .t PatentedMar.,V 5, 1 957'f Suitable e n Y 2,783,904

the. rod-26thusprovidinga relative grasping and releasing. scissor..action of.. claw.. 39.-with the.claws` 3.1..V Itwi1l.

be noted in Figure l that theclaw 39 is movable to an open positionwherein it is in substantially parallel axial alignment withthebeamsliat which vposition itis-some1. what more-than 120v degreesfromthe .claws=.31', :thus lpro-ij viding a wide grip so necessary andeffective for handling concrete slabs. AAt itsrearfend, thehydraulic-ram48'. is pivotally united `at 4910 a cross brace.25;

From the foregoing description it isfobvioussthat the..

gripping-device maybe quickly attachedto or detached from lthe arm-18 bymanipulation of pins.37 and 47 and rod 26, thus forming adevice which isquicklyand easily applied or removedas the job requires`.- Itis obviousfrom inspection of igurel that the deviceris. particularly adapted forthrusting-the stationary vclaws 31 into the. earth to catch-the.fngers-38 under the -edge of a `concreteV slabvafterwhich thehydraulic-ran; V48 may be operated tor pivot the claw 39 towardthe-claws-3Lwherein-the ngerw40 will be thrust underthe opposing edgeofthe: slab, thus grasping or gripping the slab. Raising ofarm 18 thuslifts the slab from the earth where it-may be secured at one end to saidvehicle and having its free endh movable in a vertical plane; said loadsupport arm com,- prising a pair of transversely spaced parallely beamsrigidly united.; of a gripping device carried by the free end of saidarm; said gripping device comprising a transversely extending rodcarried at the free ends of said beams and having its end portionsterminating outwardly thereof; a sleeve concentric with said rod andintermediate said beams; bearings pressed in the ends of saidsleeve andcarried by said rod adjacent to the inner margins of said beams; a pairof transversely spaced claws Ihaving -their upper ends releasablysupported on the outer end portions of said rod and extending downwardlyat an acute angle relative to saidbeams; ilanges on said beamsspacedfrom their outer free ends; brace bars releasably securedto said flangesand secured at their opposed ends to said claws rigidly fixing the clawsrelative to saidarrn; said claws being provided with forwardy extendinglingers `disposed at substantially 90cs from the longitudinal axisthereof;-

a cooperatingpopposed claw having itsinnerend secured tosaid'sleevemidway the first named fixed claws; a leyer secured to said sleeve andxed relative to said second named claw; a manuallyk controllablehydraulic ram secured at one` end to said arm and at the opposed end tosaid lever at a point spaced from said sleeve, for selectiveoperationrofV saidsecondnamed claw toward and away i from said firstnamedclaws; said second named claw having an inturned nger on the outerend thereof; andA a stiteningbraceecured10SaideQQIttLDamedwlalv.215.11.23.: cent to the finger and extending rearwardly and ixed to saidlever.

2. In a concrete slab handling device, the combination with a tractorvehicle having a load support arm pivotally secured at one end to saidvehicle and having its free end movable in a vertical plane; off-agripping device carried by the free end of said arm and comprising apair of transversely spaced-claws releasablyrsecured in tixed relationto said arm and having forwardly/disposed fingers at their lower endsadapted to be thrust into the earth and under the edgeof a-,slabofconcrete; acoopjerating opposed claw operably united with. respecttosaidv` rsg named claws for gripping a slab by its edges and for relativescissor movement therewith; said second named claw being hingedlymovable to an open position in substantially parallel axial alignmentwith said arm, whereby to provideclearance to permit Vsaid iirst namedclaws -to penetrate the earth to a predetermined depth determined-by;

the relative position of. said second named claw with respect-to the;uppersurface of the slab; and manually controllable Ameans for selectivegripping movement of said second named claw,

3. Inga. concrete slab handling device, the combination witha tractorvehicle having a load support arm pivotally secured at one end of saidvehicle and having itsfree Vend movable ina vertical plane', of agripping device carried by the free end of said arm and comprisinga,pair of transversely. spacedclaws releasably secured in fixed`relation to said arm and having forwardly disposed ngers -at'their lowerends .adapted to be thrust into the earthand underthe edge of 'a slab ofconcrete; a cooperating opposed-claw operably united with respect tosaid first named claws for relative scissor movement therewithv forgrippingaslab by its edges; said second named claw being hingedlymovableto an open position disposed at least 120`degrees fromsaidrrst-namedclaws, wherebyV to provide clearance to permit said rstnamed claws topenetrate the earth-to a predetermined depth determined bythe-relativeposition of said second named-claw with respect to the uppersurface of the slab to bevhandled; and manually controllable means forselective gripping movement of said second named claw.

References Cited in the le of this patent UNITED STATES PATENTS GreatBritain Jan. 10, 1951

